This is a major update including a rendering engine overhaul and a number of very important fixes.

Fixes/changes:

Allow animated personas (lightweight themes)!You will need to set a preference for this, since enabling animated personas causes a small but noticeable performance loss upon start-up.To enable animated personas, go to about:config and set lightweightThemes.animation.enabled to true, then reload your persona.

Fix regularly occurring browser crashes with hardware acceleration enabled on DirectWrite 6.2/6.3 (Win 7 with Platform Update, Windows 8/8.1).Most notable on computers equipped with NVidia cards, this combination of hardware and software would be cause for regular but intermittent crashes due to an issue with hardware acceleration. As part of the overhaul, this should now be fixed.

Fix font rendering issues on DirectWrite 6.2/6.3, especially on legacy AMD hardware. (KB2670838 issues).A very long-standing issue that was already partly mitigated in Pale Moon should now be completely eliminated as part of the overhaul.

Fix Windows version detection issues on Windows 8.1.Since Microsoft changed basic parts of the Windows API in Windows 8.1, operating system detection would indicate an incorrect WINNT version number (6.2 instead of 6.3) on Windows 8.1. This would show in e.g. the UserAgent.

Shuffle reported plugin installation order to confuse trackers.Part of browser fingerprinting is the reported installation order of installed plugins in browsers. Pale Moon will now shuffle the reported order of installed plugins when enumeration is asked for, which will make it more difficult for tracking sites to individually track you. Please do note that some of the "fingerprinting tests" out there will report you as more uniquely identifying, but that is by design! This mitigation is not reducing your entropy, it is increasing it - but providing a different fingerprint each time, invalidating the fingerprints of both your presence and others' for trackers.

Clean up jumplist icons so they no longer pile up on disk on some systems (also a privacy concern).On some systems, jumplist shortcut icons would not be deleted properly, causing them to pile up in the jumplist cache folder. The problem with this is both disk space (you could have many thousands of icons) and privacy (the icons would have a date and time, and would visually indicate which sites were visited)

Change the sync server to a (new) Pale Moon sync server.As part of rolling out Australis, the Mozilla Corporation decided to also push out a new version of Sync which acts more like Google Accounts/Chrome sync, requiring a "Firefox Account". This new sync (1.5) is not compatible with older versions of Firefox or with Pale Moon, and Mozilla will also be phasing the old sync service out on the short term. As a result, I've been forced to start providing my own sync service, which will now be the default choice when you set up sync in the browser. Please carefully read the terms of service if you intend to use it.

Update the status bar code: Full-screen HTML5 video will no longer have status pop-ups overlaid.Full-screen HTML5 video would receive pop-up status messages (if the full-screen setting to that effect was enabled). This would detract from the user's viewing pleasure. Full-screen video will now get special treatment and suppress the pop-up status. Note that full screen pop-up status will still be enabled by default on other types of content (e.g. full-screen HTML5 image galleries, etc.), unless you explicitly disable it in the status bar options.

Add code to selectively ignore "autocomplete=off" on signon input fields.A good number of sites have added a restriction on signon (login) input fields to prevent autocompletion storage of those fields' content, in an attempt to "increase security". A few issues with this:

By forcing people to type the password each time, people are likely going to choose short and weak passwords.

The premise behind it seems to be that the websites "do not trust password managers" that the user has installed. It's not up to a website to decide this; Pale Moon puts you back in control.

The argument that credentials are stored automatically and compromise users' security that way doesn't apply, since storing passwords in Pale Moon is always an opt-in choice.

Code has been added to selectively ignore this autocompletion restriction so the Pale Moon password manager can effectively do its job.

Linux: reduce gstreamer CPU overhead.There have been reports of excessive CPU usage when using gstreamer video playback on Linux. This should now be fixed.

Fix styled HTML buttons to address misaligned button contents (wrong baseline).There was a bug in the Firefox layout engine causing styled input form buttons (as used by e.g. the Google Accounts chooser) to be misaligned vertically, specifically if a height was explicitly defined on the control. This should now be fixed.

Fix an old IonMonkey bug resulting in incorrect math results in some cases.Some vector operations would intermittently yield incorrect results if the IonMonkey JIT compiler was used to speed up execution. This has been a problem in IonMonkey for quite a while but the bug wasn't hit very often. This should now be fixed, and correct, repeatable results can be expected.

Improve the performance of editor initialization.Slightly speed up initialization of the editor.

Update the Pale Moon icon for better display on lower color depths.Thanks to the efforts of a fellow Pale Moon user, the Pale Moon windows icon file has received work to display better on low and medium color depth displays (e.g. over RDP or similar)

Media: use a simpler way to discard superfluous audio packets.This should help against audio/video desynchronization in some rare cases.

Security fixes:

bug #994907 - imgDecoderObserver does reference counting on different threads, so should be using thread safe reference counting.